Electrosurgical instrument

ABSTRACT

An electrosurgical forceps is provided with a shaft that extends from a housing of the electrosurgical forceps. An end effector assembly includes a pair of first and second jaw members pivotably coupled to one another via a pivot pin. One or both of the first and second jaw members may be movable from an open position for positioning tissue therebetween to a clamping position for grasping tissue. A detent is operably disposed proximal the pivot pin and extends radially outward from a proximal flange of one of the jaw members. The detent is configured to releasably engage a corresponding slot disposed on a proximal flange of the other jaw member. The detent and slot are configured to control a gap distance between the first and second jaw members when the first and second jaw members are in the clamping position.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional application of U.S. patentapplication Ser. No. 13/236,168 filed on Sep. 19, 2011, the entirecontents of which are incorporated herein by reference.

BACKGROUND

Technical Field

The present disclosure relates to an electrosurgical instrument and,more particularly, to an electrosurgical instrument including an endeffector having jaw members configured to maintain a specific “gap”therebetween when the jaw members are in a closed or clamping position.

Description of Related Art

Electrosurgical forceps are well known in the medical arts. For example,an electrosurgical endoscopic forceps is utilized in surgicalprocedures, e.g., laparoscopic surgical procedure, where access totissue is accomplished through a cannula or other suitable devicepositioned in an opening on a patient. The endoscopic forceps,typically, includes a housing, a handle assembly including a movablehandle, a shaft and an end effector assembly attached to a distal end ofthe shaft. The end effector includes jaw members configured tomanipulate tissue, e.g., grasp and seal tissue. In a monopolar jawmember configuration, one jaw member includes a seal plate and a returnpad is positioned on a patient. In a bipolar jaw configuration, each ofthe jaw members includes a respective seal plate, i.e., one seal platefunctioning as an active electrode and the other seal plate functioningas the return electrode. Typically, the endoscopic forceps utilizes bothmechanical clamping action and electrical energy to effect hemostasis byheating the tissue and blood vessels to coagulate, cauterize, seal, cut,desiccate, and/or fulgurate tissue. As is known in the art, to achieve atissue seal a specific gap needs to be maintained between the jawmembers when they are in a clamping position and tissue is positionedtherebetween.

In order to maintain a specific gap between the jaw members when tissueis grasped therebetween, one or more stop members may be positionedalong one or both seal flanges of the seal plate(s). In certaininstances, the stop members may be made from one or more insulative ornon-conductive materials, such as, for example, ceramic. The stopmembers may be secured to the seal plates via one or more suitablesecurement methods. For example, and in certain instances, the stopmembers may be secured to a seal flange of a seal plate utilizing one ormore suitable adhesives, e.g., curable adhesives. However, thistechnique is typically complicated and requires specialtyequipment/processes that increase the manufacturing cost of the sealplates, and, thus, the overall manufacturing costs of theelectrosurgical instrument. Moreover, the stop member(s) may bevulnerable to shear stress failure due to the nature of the adhesive.That is, there exists the possibility of the adhesive not curingproperly and succumbing to the shear stresses that may be present duringan electrosurgical process, i.e., during the grasping and subsequentsealing of tissue. Further, positioning the stop members on the sealflange(s) of the seal plate(s) decreases the amount of functionable oruseable sealing flange area of the seal plate. That is, the insulativenature of the stop members impedes or prevents sealing tissue that ispositioned directly about the stop members.

SUMMARY

According to an aspect of the present disclosure, an electrosurgicalforceps is provided. The electrosurgical forceps includes an endeffector assembly that includes a pair of first and second jaw membersthat are pivotably coupled to one another via a pivot pin. One or bothof the first and second jaw members may be movable from an open positionfor positioning tissue therebetween to a clamping position for graspingtissue. A detent is operably disposed proximal the pivot pin and extendsradially outward from a proximal flange of one of the jaw members. Thedetent is configured to releasably engage a corresponding slot disposedon a proximal flange of the other jaw member. The detent and slot areconfigured to control a gap distance between the first and second jawmembers when the first and second jaw members are in the clampingposition.

According to an aspect of the present disclosure, the slot may include agenerally arcuate configuration that is configured to accommodatepivotable movement of the movable jaw member. In certain instances, theslot may include an opening that is configured to receive the detent andmay be defined by two sidewalls joined by a distal wall. The detent maybe configured to contact the distal wall to maintain a predetermined gapdistance between the first and second jaw members when the first andsecond jaw members are in the clamping position.

According to another aspect of the present disclosure, anelectrosurgical forceps is provided with a shaft that extends from ahousing of the electrosurgical forceps. A longitudinal axis is definedthrough the shaft. An end effector assembly operably coupled to a distalend of the shaft includes a pair of first and second jaw memberspivotably coupled to one another via a pivot pin. The first and secondjaw members movable from an open position for positioning tissuetherebetween to a clamping position for grasping tissue. Each of thefirst and second jaw members includes a respective cam slot configuredto house a cam pin therein such that the cam pin is movable within thecam slots to move each of the first and second jaw members from the opento clamping position. In certain instances, it may prove advantageous toprovide cam slots that are angled with respect to one another. Aproximal most position of each of the cam slots includes a back wallwhereupon contact between the cam pin and the back wall of therespective cam slots corresponds to a desired gap distance between thefirst and second jaw members when the first and second jaw members arein the clamping position. In certain instances, the proximal mostposition of each of the cam slots may be aligned along a common axis.

BRIEF DESCRIPTION OF THE DRAWING

Various embodiments of the present disclosure are described hereinbelowwith references to the drawings, wherein:

FIG. 1 is a perspective view of an electrosurgical forceps according toan embodiment of the present disclosure;

FIG. 2 is schematic, plan view of a pair of jaw members associated withthe electrosurgical forceps depicted in FIG. 1;

FIG. 3 is schematic, plan view of the jaw members depicted in FIG. 2 ina closed configuration; and

FIG. 4 is schematic, plan view of a pair of jaw members according toanother embodiment of the present disclosure.

DETAILED DESCRIPTION

Detailed embodiments of the present disclosure are disclosed herein;however, the disclosed embodiments are merely examples of thedisclosure, which may be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one skilled in the art to variouslyemploy the present disclosure in virtually any appropriately detailedstructure.

Embodiments of the present disclosure are described in detail withreference to the drawing figures wherein like reference numeralsidentify similar or identical elements. As used herein, the term“distal” refers to the portion that is being described which is furtherfrom a user, while the term “proximal” refers to the portion that isbeing described which is closer to a user.

Turning now to FIG. 1, an electrosurgical endoscopic forceps 10 (forceps10) is provided having a longitudinal axis “X-X” defined therethroughand including a housing 20, a handle assembly 30, a rotating assembly70, a trigger assembly 80 and an end effector assembly 100. Forceps 10further includes a shaft 12 having a distal end 14 configured tomechanically engage end effector assembly 100 and a proximal end 16 thatmechanically engages housing 20. Forceps 10 also includeselectrosurgical cable 610 that connects forceps 10 to a generator (notshown) or other suitable power source, although forceps 10 mayalternatively be configured as a battery powered instrument. Cable 610includes a wire (or wires) (not shown) extending therethrough that hassufficient length to extend through shaft 12 in order to provideelectrical energy to at least one of the jaw members 110 and 120 of endeffector assembly 100.

Rotating assembly 70 is rotatable in either direction about alongitudinal axis “X-X” to rotate end effector 100 about longitudinalaxis “X-X.” Housing 20 houses the internal working components of forceps10, such as a drive assembly (not shown), working components of thehandle assembly, electrical raceways associated with the cable 610, andother working components therein.

With continued reference to FIG. 1, handle assembly 30 includes fixedhandle 50 and a moveable handle 40. Fixed handle 50 is integrallyassociated with housing 20 and handle 40 is moveable relative to fixedhandle 50. Moveable handle 40 of handle assembly 30 is ultimatelyconnected to the drive assembly that, together, mechanically cooperateto impart movement of jaw members 110 and 120 between a spaced-apart oropen position and an approximated or clamping position to grasp tissuedisposed between jaw members 110, 120, respectively. As shown in FIG. 1,moveable handle 40 is initially spaced-apart from fixed handle 50 and,correspondingly, jaw members 110, 120 are in the spaced-apart position.Moveable handle 40 is depressible from this initial position to adepressed position corresponding to the approximated position of jawmembers 110, 120.

Continuing with reference with FIG. 1, end effector assembly 100 isshown attached at a distal end 14 of shaft 12 and includes opposing jawmembers 110 and 120. Each of jaw members 110 and 120 includes an opposedelectrically conductive tissue sealing surface 112, 122, respectively.End effector assembly 100 is designed as a unilateral assembly, i.e.,jaw member 120 is fixed relative to shaft 12 and jaw member 110 ismoveable about a pivot 103 relative to shaft 12 and fixed jaw member120. However, end effector assembly 100 may alternatively be configuredas a bilateral assembly, i.e., where both jaw member 110 and jaw member120 are moveable about pivot 103 relative to one another and to shaft12, see FIG. 4 for example. In some embodiments, a knife assembly (notshown) is disposed within shaft 12 and a knife channel (not shown) isdefined within one or both jaw members 110, 120 to permit reciprocationof a knife blade (not shown) therethrough, e.g., via activation oftrigger 82 of trigger assembly 80.

With reference now to FIGS. 2 and 3, in addition to the respective sealplates 112 and 122, jaw members 110 and 120 each include respectiveproximal flanges 113 and 123. In the embodiment illustrated in FIGS. 2and 3, proximal flanges 113 and 123 are configured to facilitate movingone (unilateral jaw configuration) or both (bilateral jaw configuration)of the jaw members 110 and 120 from the open configuration to theclamping position and maintaining a specific gap distance “G”therebetween when the jaw members 110 and 120 are in the clampingposition. In particular, the proximal flanges 113 and 123 are configuredto provide a “hard stop” configuration, i.e., the proximal flanges 113and 123 (or portion(s) thereof) are configured to contact each other tolimit movement of the jaw members 110 and 120 toward one another. Withthis purpose in mind, one or both of the jaw members 110 and 120includes one or more stop members 104 thereon.

With continued reference to FIGS. 2 and 3, and for illustrativepurposes, stop member 104 is shown operably disposed on the proximalflange 113 of the jaw member 110, i.e., stop member 104 is operablydisposed at a position that is proximal relative to the pivot pin 103 tocontrol a gap distance between the jaw members 110 and 120 when the jawmembers 110 and 120 are in the clamping position. Alternatively, stopmember 104 may be operably disposed on the proximal flange 123 of thejaw member 120. In this particular embodiment, and in contrast to theembodiment shown in FIG. 4, stop member 104 is independent of anycamming or actuating elements of the jaw members 110 and 120.

Stop member 104 may be made from any suitable material including, butnot limited to, plastic, ceramic, metal, etc. For the purposes of thepresent disclosure, it may be assumed that stop member 104 is made froma relatively rigid plastic. Stop member 104 may be monolithically formedwith the jaw member 110 or stop member 104 may be formed and,subsequently, coupled or affixed (via one or more suitable affixationmethods) to the jaw member 110. Stop member 104 may be configured asneeded to provide a required or requisite gap distance between the jawmembers 110 and 120 when the jaw members 110 and 120 are in the clampingposition.

In particular, and in the embodiment illustrated in FIGS. 2 and 3, stopmember 104 is in the form of a detent 104 a that is configured toreleasably engage a corresponding slot 104 b operably defined on theproximal flange 123 of the jaw member 120. More particularly, detent 104a extends radially outward from the proximal flange 113 of jaw member110 and is configured to releasably engage the corresponding slot 104 bthat extends radially inward from the proximal flange 123 of jaw member120.

Slot 104 b includes a relatively arcuate configuration of suitableproportion (FIGS. 2 and 3) to accommodate the pivotable movement of thejaw member 110 when the jaw member 110 moves from the open to clampingposition and vice versa. Slot 104 b is defined by an opening 105 andthree walls including top sidewall 107, bottom sidewall 109 and distalwall 111. Distal wall 111 joins adjoining respective top and bottomsidewalls 107 and 109. The dimensions of the slot 104 b are proportionedto achieve a requisite gap distance “G” between the jaw members 110 and120. In particular, the distance that detent 104 a moves within slot 104b to contact the distal wall 111 corresponds to a specific gap distancebetween the jaw members 110 and 120, respectively, when the jaw members110 and 120 are in the clamping position (as best seen FIG. 3). Forexample, movement of detent 104 a within slot 104 b equal to about 2 mmmay correspond to a gap distance between the jaw members 110 and 120,respectively, equal to about 0.001 inches to about 0.006 inches. Inother embodiments, the gap distance between the jaw members 110 and 120may be less than 0.001 inches and greater than 0.006 inches. As can beappreciated, the specific distance that detent 104 a moves within slot104 b may be altered to achieve a specific gap distance “G” between thejaw members 110 and 120 when the jaw members 110 and 120 are in theclamping position.

In certain embodiments, the proximal flange 123 of the jaw member 120may be configured without a corresponding slot 104 b. In this instance,detent 104 a may be configured to simply contact or engage the proximalflange 123 of the jaw member 120. Alternatively, it may proveadvantageous to have each proximal flange 113 and 123 include arespective detent 304 a and 304 b (shown in phantom in FIG. 2) extendingradially outward therefrom and configured to contact each other when thejaw members 110 and 120 are in the clamping position. The specificconfiguration of the proximal flanges 113, 123 of the jaw members 110and 120 may depend on the specific needs of a manufacturer, a specificsurgical procedure, a specific gap distance “G” desired between the jawmembers 110 and 120, etc.

Positioning the stop member 104 proximal the pivot 103 or “off” the sealplates 112 and 122 when compared to conventional forceps that, as notedabove, typically, have one or more stop members positioned or secured tothe seal plates, allows for greater surface area contact or coveragebetween the seal plates 112 and 122 and tissue when tissue is positionedbetween the jaw members and the jaw members 110 and 120 are in theclamping position. Moreover, the chances or the likelihood of the stopmember 104 detaching from the seal plate are eliminated. Moreover, thecontact or surface area between the seal plates 112 and 122 and tissueis greatly increased, which, in turn, may provide a better tissue seal,e.g., a more uniform and consistent tissue seal. Further, positioningthe stop member 104 proximal to the pivot 103 or “off” the seal plates112 and 122, may reduce the cost of manufacturing the jaw members 110and 120 and/or the seal plates 112 and 122, which, in turn, may reducethe overall cost of manufacturing the forceps 10.

In use, jaw members 110 and 120 are, initially, in an open configurationto receive or position tissue therebetween (see FIGS. 1 and 2). Proximalmovement of the movable handle 40 actuates or drives a drive rod (notshown), which, in turn, moves jaw member 110 from the open configurationto the clamping position. As jaw member 110 moves from the openconfiguration to the clamping position, detent 104 a moves within theconfines of the slot 104 b until such time that the detent 104 acontacts the distal wall 111. Contact between the distal wall 111 of thedetent 104 a and slot 104 b maintains a desired gap distance “G” betweenthe jaw members 110 and 120.

With reference to FIG. 4, an end effector 200 including jaw members 210and 220 according to an alternate embodiment of the present disclosureis illustrated. Unlike the jaw members 110 and 120 each of jaw members210 and 220 is configured to move from the open configuration to theclamping position, i.e., a bilateral jaw design. In the embodimentillustrated in FIG. 4, the end effector utilizes a “hard stopconfiguration” including a pair of cam slots 230 and 240 are operablydisposed on respective proximal flanges 213 and 223 of the jaw members210 and 220. Cam slots 230 and 240 are angled with respect to oneanother such that a proximal most position of each of the cam slots 230and 240 is aligned along a common axis (as best seen in FIG. 3).

A cam pin 204 is operably disposed within the cam slots 230 and 240 andis operable to move the jaw members 210 and 220 from the openconfiguration to the closed configuration. In particular, cam pin 204 isoperably coupled to the drive rod (not shown) to provide proximal anddistal movement of the cam pin 204 within the cam slots 230 and 240.

Cam pin 204 is configured to contact proximal walls 211 and 213 of therespective cam slots 230 and 240. The proximal walls 211 and 213function similar to that of the distal wall 111 of the intent 104 b.That is, when cam pin 204 is moved a predetermined distance within thecam slots 230 and 240 and contacts the respective proximal walls 211 and213 thereof, a predetermined jaw gap distance “G” is maintained betweenthe jaw members 210 and 220.

In use, jaw members 210 and 220 are, initially, in an open configurationto receive or position tissue therebetween. Proximal movement of themovable handle 40 actuates or drives the drive rod, which, in turn,moves jaw members 210 and 220, via the cam pin 204, from the openconfiguration to the clamping position. As jaw members 210 and 220 movefrom the open configuration to the clamping position, cam pin 204 moveswithin the confines of the cam slots 230 and 240 until such time thatthe cam pin 204 contacts the proximal walls 211 and 213. Contact betweenthe proximal wall 211 and 213 of the cam slots 230 and 240 maintains adesired jaw gap distance “G” between the jaw members 210 and 220. As canbe appreciated, the unique configuration of the cam pin 204 and camslots 230 and 240 overcomes the aforementioned drawbacks that are,typically, associated with conventional forceps.

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the same. For example, in certain instances, one or more springs maybe operably associated with either of the aforementioned end effectors100 and 200. The one or more springs may be configured to provide aspecific closure force at the jaw members, 110, 210 and 120, 220.

While the aforementioned “hard stop” configurations have been describedin terms of use with an endoscopic forceps 10, it is within the purviewof the present disclosure that the aforementioned “hard stop”configurations may be utilized with various surgical instruments thatimplement a jaw configuration, e.g., open forceps, graspers, and thelike, and that require specific control of a distance between the jawmembers when the jaw members are in a clamping or closed configuration.As can be appreciated, the aforementioned “hard stop” configurations mayrequire alteration to accommodate the specific surgical instrument.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

1-4. (canceled)
 5. An electrosurgical forceps, comprising: a housinghaving a shaft extending therefrom and defining a longitudinal axistherethrough; and an end effector assembly operably coupled to a distalend of the shaft and including a pair of first and second jaw memberspivotably coupled to one another via a pivot pin, the first and secondjaw members movable relative to one another from an open position forpositioning tissue therebetween to a clamping position for graspingtissue, wherein each of the first and second jaw members includes arespective cam slot configured to house a cam pin therein, the cam pinmovable within the cam slots to move each of the first and second jawmembers from the open position to clamping position, a proximal mostposition of each of the cam slots includes a back wall whereupon contactbetween the cam pin and the back wall of the respective cam slotscorresponds to a desired gap distance between the first and second jawmembers when the first and second jaw members are in the clampingposition.
 6. An electrosurgical forceps according to claim 5, whereinthe cam slots are angled with respect to one another.
 7. Anelectrosurgical forceps according to claim 5, wherein the proximal mostposition of each of the cam slots is aligned along a common axis.
 8. Anend effector assembly for an electrosurgical forceps, comprising: afirst jaw member and a second jaw member pivotably coupled to oneanother via a pivot pin, at least one of the first jaw member or thesecond jaw member movable relative to the other from an open positionfor positioning tissue therebetween towards a clamping position forgrasping tissue therebetween, wherein the first jaw member and thesecond jaw member include a first cam slot and a second cam slot,respectively, configured to cooperate to support a cam pin therein, thecam pin movable within the first cam slot and the second cam slot tomove the at least one of the first jaw member or the second jaw memberfrom the open position towards the clamping position, each of the firstcam slot and the second cam slot defining a slot length between aproximal most portion and a distal most portion thereof, the slot lengthcorresponding to a predetermined gap distance between the first jawmember and the second jaw member when the first jaw member and thesecond jaw member are in the clamping position, wherein, when the campin is translated a distance equal to the slot length of the first camslot and the second cam slot such that the cam pin abuts the proximalmost portion of each of the first cam slot and the second cam slot, thefirst jaw member and the second jaw member are disposed in the clampingposition defining the predetermined gap distance therebetween.
 9. Theend effector assembly according to claim 8, wherein when the first jawmember and the second jaw member are disposed in the clamping position,the first cam slot and the second cam slot define an angle therebetween,the angle corresponding to the predetermined gap distance between thefirst jaw member and the second jaw member.
 10. The end effectorassembly according to claim 8, wherein the first cam slot includes afirst proximal wall at the proximal most portion thereof and the secondcam slot includes a second proximal wall at the proximal most portionthereof, wherein contact between the cam pin and each of the firstproximal wall and the second proximal wall maintains the predeterminedgap distance between the first jaw member and the second jaw member inthe clamping position thereof.
 11. The end effector assembly accordingto claim 10, wherein the first proximal wall and the second proximalwall inhibit proximal translation of the cam pin beyond the proximalmost portion of the first cam slot and the proximal most portion of thesecond cam slot.